Solubility and solvation thermodynamics of dl-nor-valine in aqueous solutions of NaCl and KCl

• Published in: Journal of molecular liquids 2015-11, Vol.211, p.294-300
• Main Authors: Roy, Sanjay, Guin, Partha Sarathi, Dolui, Bijoy Krishna
• Format: Article
• Language: English
• Subjects: dl-Nor-valine; Electrolyte; Solubility; Transfer energetics
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2015.07.030

Solubility of amino acids in aqueous solutions plays a major role in determining their thermodynamics of solvation which is further related to their biochemical and biophysical actions in human physiology. In the present study the solubility of dl-nor-valine in aqueous sodium chloride and potassium chloride solution was determined in five equidistant temperatures by using ‘formol titrimetry’ method. The thermodynamic parameters such as standard transfer Gibbs energies and entropies have been evaluated at 298.15K. Other important related parameters like molar volume, density, dipole moment and solvent diameter of the experimental solutions were also determined in this study. The above mentioned parameters were used to determine ΔGt,ch0(i) i.e. chemical effects of the transfer Gibbs energies and ΤΔSt,ch0(i) i.e. chemical effects of the transfer entropy. Different factors such as nature of solute and solvent, interactions between solute and solvents, etc., influencing the solvation of dl-nor-valine were characterized by different physical and analytical approaches. [Display omitted] •Solubility of dl-nor-valine in aqueous sodium chloride and potassium chloride solution were measured.•The standard transfer Gibbs energies and entropies were evaluated at 298.15K.•The ΔGt,ch0(i) i.e. chemical effects of the transfer Gibbs energies and ΤΔSt,ch0(i) i.e. chemical effects of the transfer entropy were explained.•The dipole–dipole and cavity forming interactions in such electrolyte system stabilize the present amino acid.•The chemical stability of dl-nor-valine is higher in KCl-water system than the NaCl-water system.